<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="vue.js"></script>
</head>
<body>
    <div id="app">
        <div v-if="isShow" ref="self">test</div>
        <button @click="isShow">更新</button>
    </div>
    <script>
        var vm = new Vue({
            el: '#app',
            data:{ isShow:false},
            beforeUpdata(){
                console.log('更新之前')
                console.log(this.$refs.sele)
            },
            updataer (){
                console.log('更新之后')
                console.log(this.$refs.sele) 
            }
        })
    </script>
</body>
</html>